Serena Williams has avoided a ban from tennis but has been fined for her outburst during the US Open final.

The former world No. 1 was given a code violation for verbal abuse of the chair umpire, accusing Eva Asderakia of being "out of control" and "unattractive inside".

Playing under a suspended ban from the 2009 final when she launched a verbal attack on a line judge at Flushing Meadows, Williams could have been barred if tournament officials felt her actions constituted a major offence.

However, her actions were not deemed serious enough to warrant a ban, although the 13-time grand slam champion, who fell in straight sets to Sam Stosur in Sunday's final, has been slapped with a $2000 fine.

"US Open tournament referee Brian Earley has fined Serena Williams US$2000 following the code violation issued for verbal abuse during the women's singles final," said a statement by the US Tennis Association.

"This fine is consistent with similar offences at grand slam events. As with all fines at the US Open, the monies levied are provided to the Grand Slam Development Fund which develops tennis programmes around the world.

"After independently reviewing the incident which served as the basis for the code violation, and taking into account the level of fine imposed by the US Open referee, the grand slam committee director has determined that Ms Williams' conduct, while verbally abusive, does not rise to the level of a major offence under the grand slam code of conduct."